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Old Mar 7, 2005, 10:34 AM   #1
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My 20D c/w 17-85 IS lens have just arrived. Like a kid at Christmas I couldn't stop myself rushing out into the garden and shooting some spring flowers, the cat etc.

Having come from a G2 digi compact, it is great to have an slr back in my hands. The G2 was good and has taken thousands of shots but every so often it took over and decided how 'it' wanted a photo taken

First impressions of the 20D are excellent. Colours are very true and well saturated (usingjpeg at the moment) and the lens seems on a par with my old 20-135 USM IS. I can't wait to really get to grips with this thing and take some real shots.



While pondering whether to get a DSLR, all the talk of stuck pixels and sensor dust has been a little disconcerting. I guess that before I go too much further, I should perform a check for dust and pixels.

Question is...... How do you do this?

Any advice on procedures (and what to do if the results are not good) gratefully recieved.

Nick.
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Old Mar 7, 2005, 10:44 AM   #2
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Good choice :-)Congrats!

For sensor dust, I tend to not go specifically looking for it, until I notice it in my images. Whenthe amount starts to become too objectionable I use the brushes from http://www.visibledust.com/. No chemicals, just a swipe or two with an electro-statically charged brush.


Maybe I'm Lucky, I've only had to clean mine twice since I gotthe Cameralast October, and one of those times was my fault for deciding to change to a wide-angle lens while shooting in a sawdust filled wood-shop. (I should have knowed-better and stepped outside:blah.


For stuck pixels, I have never thought about it :-), I guess you could take a dark-frame and see if any pixels are on.I think there may even be some programs availableto check for this too, but I am not sure.

Peter.
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Old Mar 7, 2005, 11:22 AM   #3
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dead pixels are very very very common. the easiest way i can find them is to set the ISO to 100 and do a 30 sec exposure with the lens cap on. i assure you that when you transfer the picture to the computer you will see some white and or colored pixels. i do not worry about them because i have also found that those bad spots only show up with exposures longer than 10 or so secs. every slr that i have tried this on is the same way (D70, Rebel, Rebel XT, 10D, 20D)


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Old Mar 7, 2005, 12:14 PM   #4
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Thanks for your replies.

I tried the 30 sec exposure and it (as you suggest) does show a few stuck pixels. Only 5 or so, so probably not worth getting too concernd about (yet).

Also tried a dust test by taking a long exposure of a plain colour (sheet of A4 paper on the table) with the aperture set to f22.

The combined image is attached. The red areas are the stuck pixels (the size is diagrammtic as the area effectedare much, much smaller). The mud coloured splodges are I am guessing sensor dust. Is this at the stage where I should consider cleaning the sensor or can I happily fire away for the moment?

Also is this normal for a just delivered DSLR?

Thanks for your help.
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Old Mar 7, 2005, 12:57 PM   #5
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Yikes that looks worse than mine did after a couple of months of use, I can't speak for others, but mine came from the store with a clean sensor.

I triedthe stuck pixel test just to annoy myself :lolosen't look bad.

Shoot at ISO 100, 30 seconds, F32, lens cap on, canera in a the camera bag in a dark room.

Peter.

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Old Mar 7, 2005, 10:11 PM   #6
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im so retarded...... i looked at the last post and couldnt find the picture

duh... its black:lol:
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Old Mar 7, 2005, 11:24 PM   #7
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:blah:Ya, all black,no pixels stuck on. Some day will have to get around to trying the other half of the test to see if any pixels are stuck off.

I suspect PhotoEcosse camera might just need a good cleaning, the specks look like dust and I'm not sure what the larger blobish areas are, to me they look more like dried moisture maybe from condensation. In any case I'd be asking the manufacturer about it. IMHO: A new camera should not come looking quite like that.

Peter.
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Old Mar 8, 2005, 2:08 AM   #8
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Peter, Thanks, you have reassured me that I'm not completely paranoid about dust.

Looks like a sensor clean is required. I know it has been asked before but what would folk recommend as the easiest / most effective route for a first timer??
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Old Mar 8, 2005, 9:56 AM   #9
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You just gotthe camera,so the first thing I'd try is to go to a Canon service center and complain to them. IMHO: They should clear it for free.

After that the visibledust brushes and sensorclean pads seem to work well. I've never tried any of the other cleaning wipes, heard mixed results about them (which is what prompted me to get the visibledust stuff in the first place)

Review of the visibledust brushes from luminous-landscape http://www.luminous-landscape.com/re...ble-dust.shtml

Peter.
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Old Mar 9, 2005, 9:29 PM   #10
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Here's a link for a free dead / hot pixel test.



http://www.starzen.com/imaging/deadpixeltest.htm



I ran it on a new dig camera and compared three different cameras - and kept the best one. There was a BIG difference in number/intensity of hot pixels between the three (not a Canon)



Bob


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